The present invention relates to catalysts for bulk polymerization and vapor-phase polymerization of an xcex1-olefin compound, methods for polymerizing an xcex1-olefin compound by using the catalysts, and olefin polymers obtained by using the catalysts.
To say in detail, the present invention relates to catalysts for bulk polymerization and vapor-phase polymerization, each of the catalysts has high polymerization activity during bulk or vapor-phase polymerization of an xcex1-olefin compound as a raw material monomer, and each of the catalysts provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen; methods for polymerizing an xcex1-olefin compound by using the catalysts; and olefin polymers obtained by using the catalysts.
Up to now, as a catalyst for polymerizing an xcex1-olefin compound and fabricating an olefin polymer, Ziegler type catalyst is well known. Examples of these catalysts are disclosed in Japanese publication of unexamined patent application No. Hei-2-163104 and Japanese publication of unexamined international patent application No. Hei-8-509263.
To give an actual example, the catalyst, disclosed in Japanese publication of unexamined patent application No. Hei-2-163104, comprises the following ingredients (A1) to (C1).
(A1) a solid catalyst ingredient including trivalent titanium, the ingredient is obtained by the following steps;
reducing halogenated titanium by an organomagnesium compound under a presence of an organosilicon compound having a Sixe2x80x94O bonding to thereby form a solid product,
treating the solid product with an ester compound, and then
treating the solid compound with a mixture of an ether compound, titanium tetrachloride, and an ester compound;
(B1) an organoaluminum compound; and
(C1) dialkyldialkoxysilane and the like.
The catalyst, disclosed in Japanese publication of unexamined international patent application No. Hei-8-509263, comprises the following ingredients (A2) to (C2).
(A2) a solid compound including magnesium atoms, halogen atoms, and transition metal atoms such as titanium;
(B2) an organoaluminum derivative; and
(C2) dialkyldialkoxysilane and the like.
By the way, in general, when an xcex1-olefin compound is bulk polymerized or vapor-phase polymerized, a melt flow rate (MFR) is heighten by using a chain transfer agent, such as hydrogen, and thereby lower a molecular weight of an olefin polymer.
However, the catalysts, disclosed in Japanese publication of unexamined patent application No. Hei-2-163104 and Japanese publication of unexamined international patent application No. Hei-8-509263, have the following problems.
(1) Although an olefin polymer having an excellent stereoregularity is obtained by bulk polymerization or vapor-phase polymerization, a melt flow rate against the hydrogen using amount is small. As a result, the catalyst is unfavorable for fabricating an olefin polymer having a high melt flow rate.
To give an actual example, referring to FIG. 1, when hydrogen partial pressure during bulk polymerization is 0.25 MPa (gauge), MFR (in accordance with JIS-K7210) of the obtained olefin polymer is about 1.2 g/10 min. Whereas, when hydrogen partial pressure is increased to 1 MPa (gauge), MFR of the obtained olefin polymer is about 14 g/10 min
Further, referring to FIG. 2, when hydrogen partial pressure during vapor-phase polymerization is 0.01 MPa (gauge), MFR (in accordance with JIS-K7210) of the obtained olefin polymer is about 0.03 g/10 min. Whereas, when hydrogen partial pressure is increased to 0.09 MPa (gauge), MFR of the obtained olefin polymer is about 2.5 g/10 min
That is to say, with respect to the conventional catalyst, a large quantity of hydrogen should be used in order to lower the melt flow rate of the olefin polymer.
(2) When an olefin polymer having a high melt flow rate is fabricated by bulk polymerization or vapor-phase polymerization by using the above catalyst, the stereoregularity of the obtained olefin polymer is deteriorated.
That is to say, since the stereoregularity and the melt flow rate of the olefin polymer are conflict properties in general, in order to fabricate an olefin polymer having a high melt flow rate, the stereoregularity is deteriorated. As a result, heat resistance and creep resistance of the olefin polymer are deteriorated.
(3) When an olefin polymer having a high melt flow rate is fabricated by bulk polymerization or vapor-phase polymerization by using the above catalyst, much more hydrogen is needed. As a result, in view of safety, high pressure resistance of the manufacturing equipment should be needed.
(4) Further, with respect to the catalyst, when a large quantity of hydrogen is used, hydrogen partial pressure during bulk polymerization or vapor-phase polymerization is heightened and thereby partial pressure of the monomer is lowered. As a result, productivity of the olefin polymer is deteriorated.
Under the circumstances, catalysts, having high polymerization activity during bulk polymerization or vapor-phase polymerization, and providing an olefin polymer having desired molecular weight and melt flow rate by adding a small amount of hydrogen, is needed.
Therefore, the present invention is acquired in view of the above problems. The object in accordance with the present invention is to provide a catalyst for bulk polymerization or vapor-phase polymerization, the catalyst having high polymerization activity during bulk polymerization or vapor-phase polymerization and providing an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen by combining a specific solid catalyst, an organoaluminum compound and a specific organosilicon compound.
In addition, the object in accordance with the present invention is to provide methods for bulk polymerization and vapor-phase polymerization, the methods effectively provide an olefin polymer having excellent properties in melt flow rate and stereoregularity by using the catalysts for bulk polymerization and vapor-phase polymerization.
In addition, the object in accordance with the present invention is to provide an olefin polymer, having excellent properties in melt flow rate and stereoregularity, obtained by using the catalysts for bulk polymerization and vapor-phase polymerization.
[1] One embodiment in accordance with the present invention (First invention) is a catalyst for bulk polymerization of an xcex1-olefin compound under a presence of hydrogen, the catalyst is made by contacting the following ingredients (A) to (C). Further, the other embodiment in accordance with the present invention (Second invention) is a catalyst for vapor-phase polymerization of an xcex1-olefin compound under a presence of hydrogen, the catalyst is made by contacting the following ingredients (A) to (C).
(A) a solid catalyst ingredient, comprising:
(a) a magnesium compound,
(b) titanium tetrachloride, and
(c) dialkyl phthalate (Each of the alkyl groups denotes a straight-chain or branched-chain hydrocarbon group having a carbon number of 3 to 20.);
(B) an organoaluminum compound; and
(C) an organosilicon compound, which is expressed by the following general chemical formula (1).
(R1)(R2CH2)Si(OR3)(OR4)xe2x80x83xe2x80x83(1)
[In the general chemical formula (1), R1 denotes a alicyclic hydrocarbon group having a carbon number of 3 to 12, R2 denotes a branched-chain hydrocarbon group having a carbon number of 3 to 20, and each of R3 and R4 denotes a hydrocarbon group having a carbon number of 1 to 20, respectively.]
As an ingredient (C), by using the specific alicyclicalkyldialkoxysilane as an outside donor, polymerization activity may be improved. As a result, a catalyst for bulk polymerization or vapor-phase polymerization, which provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen, may be provided.
[2] In accordance with the first invention or the second invention, each R1 of the ingredient (C) is preferably a cyclopentyl group or a cyclohexyl group.
As an ingredient (C), by using the specific alicyclicalkyldialkoxysilane as an outside donor, polymerization activity may be more improved. As a result, a catalyst for bulk polymerization or vapor-phase polymerization, which provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen, may be provided.
[3] In accordance with the first invention or the second invention, each of the ingredient (C) is preferably cyclopentylisobutyldimethoxysilane or cyclohexylisobutyldimethoxysilane.
As an ingredient (C), by using the specific alicyclic dialkyldialkoxysilane as an outside donor, polymerization activity may be much more improved. As a result, a catalyst for bulk polymerization or vapor-phase polymerization, which provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a smaller amount of hydrogen, may be provided.
[4] In accordance with the first invention or the second invention, each of the ingredient (C) is preferably an organosilicon compound obtained by the following chemical reaction formula.
R2CH2Si(OR3)2(OR4)+R1MgBrxe2x86x92R1(R2CH2)Si(OR3)(OR4)+MgBr(OR3)
[In the chemical reaction formula, each of R1, R2, R3 and R4 denotes the same as R1, R2, R3 and R4 in the chemical general formula (1), respectively.]
Since the ingredient (C) is the organosilicon compound obtained by the above method, the obtained catalyst may become to have high purity and may be made at a low cost. Therefore, polymerization activity may be much more improved. As a result, a catalyst for bulk polymerization or vapor-phase polymerization, which provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen, may be provided.
[5] In accordance with the first invention, catalytic activity is preferably 600 Kg/gTi or higher. In accordance with the second invention, catalytic activity is preferably 700 Kg/gTi or higher.
Since, each of the catalysts for bulk polymerization and vapor-phase polymerization has each of the above catalytic activities, polymerization activity for an xcex1-olefin compound may be improved certainly and polymerization condition may become controlled easily.
[6] In accordance with the first invention or the second invention, it is preferably that the ingredient (A) further comprises a solid catalyst ingredient obtained by contacting silicon tetrachloride as an ingredient (d).
Since the catalyst for bulk polymerization or vapor-phase polymerization includes an inside donor, polymerization activity may be more improved. As a result, a catalyst for bulk polymerization or vapor-phase polymerization, which provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen, may be provided.
[7] In accordance with the first invention or the second invention, the ingredient (A) is preferably a solid catalyst ingredient obtained by a method comprising the following steps of i) to iii) in order.
i) contacting (a) a magnesium compound with (d) silicon tetrachloride,
ii) contacting (c) dialkyl phthalate (Each of the alkyl groups denotes a straight-chain or branched-chain hydrocarbon group having a carbon number of 3 to 20.), and
iii) contacting (b) titanium tetrachloride under a high temperature condition.
Since the solid catalyst ingredient is obtained by contacting (b) titanium tetrachloride and the like in order, (b) titanium tetrachloride may be supported fully and strongly onto the (a) magnesium compound. As a result, polymerization activity may be more improved and thereby a catalyst for bulk polymerization or vapor-phase polymerization, which provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen, may be provided.
[8] In accordance with the first invention or the second invention, the ingredient (A) is preferably a solid catalyst ingredient obtained by the method comprising the following steps of i) to iv) in order.
i) contacting (a) a magnesium compound with (d) silicon tetrachloride,
ii) contacting (c) dialkyl phthalate (Each of the alkyl groups denotes a straight-chain or branched-chain hydrocarbon group having a carbon number of 3 to 20.),
iii) contacting (b) titanium tetrachloride under a high temperature condition, and iv) after washing with a hydrocarbon solvent, adding and contacting (b) titanium tetrachloride under a high temperature condition.
Since the solid catalyst ingredient is obtained by contacting (b) titanium tetrachloride multiple times, (b) titanium tetrachloride may be supported fully and strongly onto the (a) magnesium compound. As a result, polymerization activity may be more improved and thereby a catalyst for bulk polymerization or vapor-phase polymerization, which provides an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen, may be provided.
[9] The other embodiment in accordance with the present invention (Third invention) is a method for bulk polymerizing an xcex1-olefin compound under a presence of hydrogen by using a catalyst for bulk polymerization, the catalyst is made by contacting the following ingredients (A) to (C), and the other embodiment in accordance with the present invention (Forth invention) is a method for vapor-phase polymerizing an xcex1-olefin compound under a presence of hydrogen by using a catalyst for vapor-phase polymerization, the catalyst is made by contacting the following ingredients (A) to (C).
(A) a solid catalyst ingredient, comprising:
(a) a magnesium compound,
(b) titanium tetrachloride, and
(c) dialkyl phthalate (Each of the alkyl groups denotes a straight-chain or branched-chain hydrocarbon group having a carbon number of 3 to 20.);
(B) an organoaluminum compound; and
(C) an organosilicon compound, which is expressed by the above general chemical formula (1).
[10] In accordance with the third invention or the forth invention, hydrogen partial pressure is preferably within the range of 0.01 to 5 MPa.
Putting the above methods for bulk polymerization and vapor-phase polymerization into practice, the melt flow rate and the stereoregularity of the obtained olefin polymer may be well balanced easily. In addition, since hydrogen partial pressure is within the above range, polymerization activity may become an appropriate value, and pressure resistance design of the receptacle may become easier.
[11] In accordance with the third invention or the forth invention, the xcex1-olefin compound is preferably propylene.
[12] The other embodiment in accordance with the present invention (Fifth invention) is an olefin polymer obtained by bulk polymerization of an xcex1-olefin compound under a presence of hydrogen by using a catalyst for bulk polymerization, the catalyst comprises the following ingredients (A) to (C), and the other embodiment in accordance with the present invention (Sixth invention) is an olefin polymer obtained by vapor-phase polymerization of an xcex1-olefin compound under a presence of hydrogen by using a catalyst for vapor-phase polymerization, the catalyst comprises the following ingredients (A) to (C).
(A) a solid catalyst ingredient, comprising:
(a) a magnesium compound,
(b) titanium tetrachloride, and
(c) dialkyl phthalate (Each of the alkyl groups denotes a straight-chain or branched-chain hydrocarbon group having a carbon number of 3 to 20.);
(B) an organoaluminum compound; and
(C) an organosilicon compound, which is expressed by the above general chemical formula (1).
[13] In accordance with the fifth invention or the sixth invention, the melt flow rate of the olefin polymer, measured under the conditions of 230xc2x0 C. and 2.16 Kgf/cm2 according to JIS-K7210 standard, is preferably within the range of 0.01 to 500 g/10 min.
Since the olefin polymers have the above melt flow rate, the flow ability and the stereoregularity may be well balanced easily.
[14] In accordance with the fifth invention, where the absolute value of the melt flow rate of the olefin polymer is MI, where hydrogen partial pressure during bulk-polymerization is PH (MPa), and where total pressure during bulk polymerization is PT (MPa), the following equation (2) is met.
MIxe2x89xa71.0 exp(10.5xc3x97PH/PT)xe2x80x83xe2x80x83(2)
Further, in accordance with the sixth invention, where the absolute value of the melt flow rate of the olefin polymer is MI, where hydrogen partial pressure during vapor-phase polymerization is PH (MPa), and where total pressure during vapor-phase polymerization is PT (MPa), the following equation (3) is met.
MIxe2x89xa70.045 exp(155xc3x97PH/PT)xe2x80x83xe2x80x83(3)
Since the above equations (2) and (3) are met, olefin polymers having an excellent melt flow rate may be provided.
[15] In accordance with the fifth invention or the sixth invention, an amount of a heptane-insoluble ingredient of the olefin polymer, measured by Soxhlet extractor under the conditions of using a boiling heptane solvent and 5 hr of extraction, is preferably 90 weight % or higher.
Since an amount of a heptane-insoluble ingredient is within the above range, olefin polymers having an excellent stereoregularity may be obtained.